'ROS2' -> 'ROS 2' in README (#32)

Signed-off-by: Christophe Bedard <[email protected]>

Author: christophebedard

README.md

@@ -5,7 +5,7 @@
 [![Build and Test (jazzy)](../../actions/workflows/build_and_test_jazzy.yaml/badge.svg?branch=jazzy)](../../actions/workflows/build_and_test_jazzy.yaml?query=branch:jazzy)
 [![Build and Test (rolling)](../../actions/workflows/build_and_test_rolling.yaml/badge.svg?branch=rolling)](../../actions/workflows/build_and_test_rolling.yaml?query=branch:rolling)
 
-Basic ROS2 wrapper for the zbar (http://zbar.sourceforge.net/) barcode reader library. Reads image stream from `image` topic, and outputs detected barcodes to `barcode` topic. Works with 1D and 2D barcodes.
+Basic ROS 2 wrapper for the zbar (http://zbar.sourceforge.net/) barcode reader library. Reads image stream from `image` topic, and outputs detected barcodes to `barcode` topic. Works with 1D and 2D barcodes.
 
 ![Usage](images/usage.gif)